Research on Eddy-Current Testing of Functional Polymer Composite Material

Polymer composite materials mixed with conductive particles can be used as electromagnetic interference shielding and absorbing materials. Considering the extreme environmental conditions of coating stealth weapons and forming mobile signal shields, it is necessary to develop a non-destructive test of these materials, as the function of shielding and absorbing would not work if the object has some discontinuous areas. In this paper, the eddy-current effect of polymer composite materials with discontinuous conductors was tested, and a finite-element model and a high-frequency (similar to MHz) eddy-current testing system were developed. The induced voltage occurred on the surface of the composite objects, leading to skin effect. The study results show that the reactance response changes depend on the liftoff distance. Thus, the feasibility of high-frequency electromagnetic test measured in the discontinuous areas of the continuous conductive polymeric material surfaces can be verified.